Global System for Mobile Communication (GSM) is one of the most popular technologies in wireless data communication. On the other hand, Internet is the most popular choice for wired communication. Although both communication network systems were widely deployed, there was little data exchange between the two networks in the early age. This is because these two networks use different data exchange methods. While GSM uses circuit-switch for data exchange, Internet uses packet-switch for data transmission. It is difficult to conduct data exchange between the two networks.
General Packet Radio Service (GPRS) is a technology proposed for solving the above problem. The emergence of the technical standard of GPRS facilitates the data exchange between the two networks. GPRS is a new packet data transmission service based on GSM, with addition of new data exchange points in the current GSM network. As the new data exchange points are capable of processing packets, the GSM network can exchange data with Internet network. The convenience of GSM wireless transmission is added to the information-rich Internet for easy sharing.
The major difference between the GPRS and the GSM is that GSM is circuit-switching, while GPRS is packet-switching. Therefore, GPRS is suitable for discontinuous and bursty data traffic, or frequent and small amount data traffic. It is also suitable for occasional large amount data traffic.
The GPRS cards are generally used in mobile computers and PDAs as the means for wireless communication, so that they can be connected to Internet through mobile phones. A conventional GPRS card usually consists of a motherboard installed with mandatory components, such as a GPRS communication module and a battery set. Conventional GPRS cards also use a specific interface, such as Compact Flash, for interfacing other systems. However, as the GPRS card cannot be connected to the system unless a suitable interface is used, it usability is limited. Alternatively, a PC or a PDA can be used to complete the device, but it greatly increases the cost.